Translation of messages in Shibboleth IdP 5

[Cantor, Scott]

For now, I've populated two directories:

/java-identity-provider/messages/
/java-identity-provider/attributes/
/java-idp-plugin-totp/messages/

I'm not finding any message files (with anything in them) in any other plugins, but if I'm overlooking anything, I'll add them.

For the time being I left each message set in those folders and didn't bother creating language subdirectories, but if that's useful for some reason I'm not aware of we can move them under more folders obviously.

Also included the attribute descriptions and such from the transcoder rules in the attributes folder.

There are definitely missing translations across all these.

As a workflow issue, we will definitely diff these files when we start getting close to any releases, and given how rarely we change the messages or other files, I'll drop a heads up here if we do.

-- Scott